"There are five levels of darkness and at the darkest you can sleep very comfortably but you're still able to look outside."

Passengers can dim the windows via a button at the base of the window but they're not the only ones in control of the amount of light coming in.

"With one press of the button in the cabin control centre at the front, the flight attendants can control every window," Dr Ornan-Stone said.

"It's really important that everybody has the opportunity to have an uninterrupted sleep and not to have to worry about someone who wants to peek outside and fill the cabin with light. We wanted to make sure that sleep is guaranteed and that flight attendant's have control."

The electronic dimming feature isn't the only remarkable thing about the windows on the Dreamliner planes.

"The windows are the first thing you'll notice when you walk on board a Qantas plane. They're not the only the largest and the widest but they're also the best positioned of any aircraft window flying today and they were designed so that a middle seat passenger can look out the window without having to crane their neck."

Qantas will use their Dreamliners for flights between Melbourne to Los Angeles from December and in March next year the planes will also start flying from Perth to London.Boeing 787-9 Dreamliner joins the Qantas International fleet from December.

Andrew Bucklow was a guest of Qantas and Boeing at the Boeing factory in Everett.